This inventions concerns computer inputs, and particularly object pointer input devices.
Most prior art keyboard devices use the concept of discrete keys. The keys require interconnect wires implemented in a keyboard composed of multiple keys. One prior art device codes each key with multiple switches. The switches may be optical sensors. A group of one or more sensors is dedicated to a particular key. When a key closure occurs, the code of that key can be detected on the interconnect wires. The appearance and use of that prior art keyboard would be like any standard keyboard in use today. The implementation of the key electronics is the only difference. Mechanical keys are replaced with coded optical keys. Multiple sensors are involved in detecting a key. The use of multiple sensors for one key is inefficient. As an example, one device requires 36 sensors for 14 keys.
One prior art device requires a special light source in an enclosure. Multiple sensors make up a key, and each individual key must be uniquely fabricated and interconnected. Keys are not interchangeable.
In another keyboard which is similar because it uses the same discrete key concept, a switch is a single emitter-receiver sensor pair. The light path between the two is broken to produce a key closure.
One touch screen uses a finger or similar object to point to a location in a rectangular area. The rectangular area has optical transmitters and receivers on its boarders. Resolution is determined by the size of the object used for pointing.
Another prior art device uses optical sensors and detects coordinates. There are major differences in the technology and method used for determining coordinates in that device. A major portion is mechanical and uses motors, slotted belts and rotating drums to scan a defined area for an object. Parabolic mirrors concentrate lights that must span the x and y coordinates. Synchronization of the moving parts to electronic counters is required to determine coordinates. The rate of change if determined by the speed of the moving parts. Resolution is determined by the object used for pointing, the quality of the optics, and the mechanical-to-electronic interface tolerances.
One prior art device requires a pointer that breaks a plane of light to the sensors. The pointer is positioned perpendicular to the plane of light. Pointers would typically be thin cylindrical objects, like pencils, fingers, etc. The ability to determine a coordinate is determined by the diameter of the pointer and the quality of the optics.
A need exists to provide simplified electronic inputs which provide versatility and accuracy using common objects as pointers.